This invention relates to electronically addressed displays which are capable of displaying alpha-numeric, graphic, and pictorial information translated from an electrical signal supplied to the display. Such displays are widely used in computer terminals, word processors, and other information-handling equipment where it is desired to view electronically stored or transmitted information of an alpha-numeric, graphic, or pictorial nature. More specifically, this invention relates to an electronically addressed electro-optical display which is compact, relatively thin, portable, and yet having a display size, resolution and contrast permitting the display of page sized, typewritten, alpha-numeric, graphic and pictorial information. As was described in the aforementioned parent application Ser. No. 916,740, the disclosure of which is completely and entirely and specifically incorporated by reference herein, an electronic display is provided with an assembly of individual, electrically addressable display elements, arrayed in a plurality of rows and columns, with a corresponding array of lenses, each of the display elements being aligned with and on the optical axis of a respective one of the lenses. The display elements are of either the reflective or transmissive liquid crystal variety, with an illumination source being provided in a manner corresponding to the nature of the display element.
In embodiments wherein it is specifically desired to employ reflective display elements, it has been found that greater structural integrity and ease of assembly is realized by having a source of rear illumination. However, rear illumination is not effective in reflective elements, since the source of illumination is required to be incident upon the reflective element from the same side as the optical axis of the lens. The difficulty with providing illumination from the same side of the display element as the optical axis is evident from an examination of the relative dimensional spacings between the reflective element and its associated lens, as well as other difficulties in introducing pluralities of light sources in and around the projection lens area.
It is therefore the primary object of the present invention to provide a novel and unique arrangement for illumination of reflecting display elements when the illumination of introduced from a source opposite the reflected side of the display element.
A further object of the present invention is to provide a plurality of means, arrayed along a common surface, to implement the direction of the illumination onto the reflective side of the display element over an entire array of such display elements.